Reverse osmosis filter cartridge assembly

Abstract

A three element reverse osmosis filter cartridge assembly has a pre-filter section for solid particles, a reverse osmosis membrane filter section which produces product water and waste water from feed water circulated thereto via the pre-filter section, and a post-filter section for filtering the product water. These sections are disposed in coaxial, concentric relationship. The pre-filter section forms a replaceable outside sheath which is slideable onto and off the membrane section. The post-filter section is a tubular body containing carbon or other particles which is removably disposed in a central opening inside the membrane section. The membrane section has a support ring defining one end of the cartridge assembly which is disposed in sealing relationship with a ring which holds filter media layers of the pre-filter section. The pre-filter section has another ring at the end thereof opposite to said first ring and defines the opposite end of said pre-filter section. The cartridge assembly is replaceably disposed in a tubular housing having an end plate at one end thereof and a removable end cap at the opposite end thereof. The end plate has openings or ports for communicating feed water into said pre-filter section and for the out feed of waste water and product water from said membrane section and post-filter section, respectively. The cartridge assembly may be removed as an integral unit from the tubular housing when the end cap is removed, and the three sections thereof are each replaceable independently so that either an entire cartridge unit or the cartridge unit with a fresh pre-filter section, a fresh post-filter section or a fresh membrane section can be replaced in the housing.